1,796 research outputs found

    Performance Characteristics of Venturi Tubes Used in Aircraft for Operating Air-driven Gyroscopic Instruments

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    Wind tunnel and flight tests were made to determine the performance characteristics of two designs of commercially available venturi tubes used in airplanes to operate air-driven gyroscopic instruments. Data obtained at sea level may be used to make approximate predictions of performance at higher altitudes. There is some indication that this may also be done for single venturi tubes. For a given installation in which an air-driven instrument is connected through tubing with a venturi tube, the volume rate of induced air flow is approximately proportional to the product of indicated air speed and the square root of the ratio of standard to ambient air pressure. The efficiency of such a system at a given altitude is constant. Rather large variations in suction and efficiency were found for individual tubes of the same design. Cylindrical fairings on the external surface resulted in a reduction of both drag and suction but little change in efficiency

    Women, Youth and the Economic Crisis in Southern Europe

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    __Abstract__ The paper raises questions about how the economic crisis is being played out ‘in place’ taking an embodied, generational and gender perspective. We place in a political context – examining how global realities are experienced in place and argue that we need to look at the every day realities of the crisis from a gendered and generational perspective in order to counter grand narratives of gloom and doom where women (whether old, young, migrant, heterosexual or otherwise) are particular victims. We seek to show how by contextualizing the gendered and generational realities of the crisis in southern Europe can we change the narrative of overwhelming paralyzing crisis to one of potential transformation. We focus on the rise of resistance, solidarity economies and new types of communities in the search for alternatives to neoliberal capitalism by women and youth in southern Europe. We look at how people are organizing differently as a result of the crises, creating news forms of political economic and social relations. Dominant narratives tend to exclude the stories of the unprivileged in such reshapings of political, economic and social relations, this paper is the beginnings of bringing the experience and understandings of women and youth in southern Europe to the centre of the analysis of the economic crisis in Europe

    Information dynamics shape the networks of Internet-mediated prostitution

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    Like many other social phenomena, prostitution is increasingly coordinated over the Internet. The online behavior affects the offline activity; the reverse is also true. We investigated the reported sexual contacts between 6,624 anonymous escorts and 10,106 sex-buyers extracted from an online community from its beginning and six years on. These sexual encounters were also graded and categorized (in terms of the type of sexual activities performed) by the buyers. From the temporal, bipartite network of posts, we found a full feedback loop in which high grades on previous posts affect the future commercial success of the sex-worker, and vice versa. We also found a peculiar growth pattern in which the turnover of community members and sex workers causes a sublinear preferential attachment. There is, moreover, a strong geographic influence on network structure-the network is geographically clustered but still close to connected, the contacts consistent with the inverse-square law observed in trading patterns. We also found that the number of sellers scales sublinearly with city size, so this type of prostitution does not, comparatively speaking, benefit much from an increasing concentration of people

    PEGASUS: the Design of an Intervention to Facilitate Shared Decision-making in Breast Reconstruction

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    © 2020, The Author(s). Studies have found varying levels of satisfaction after breast reconstruction surgery with a substantial group of patients reporting some level of regret about their decision. The variable outcomes reported by women undergoing breast reconstruction surgery suggest a role for improved pre-operative communication and shared decision-making (SDM) between patient and health professional. Pragmatic approaches such as decision aids have been evaluated, but the aim of the Patient Expectations and Goals Assisting Shared Understanding of Surgery (PEGASUS) intervention is to facilitate closer interaction between the patient and clinical team. PEGASUS is a standardised two-stage process, in which patients’ goals are first elicited, ranked in importance and recorded before being used to frame discussion and decision-making with the surgeon managing care. Following the Medical Research Council (MRC) model, feasibility and acceptability studies have already been reported and a 4-year multicentre randomised controlled trial of 180 participants is underway, (completion 2020). This paper therefore focuses on the design of the intervention itself, in line with recent advice that interventions, in comparison with evaluations, commonly lack a theoretical base and are often under reported. We report a retrospective application of the Capability, Opportunity, Motivation-Behaviour (COM-B) model to provide explicit detail of each step in the intervention design. This is intended to facilitate replication by other clinicians and to provide systematic guidance for others wishing to develop PEGASUS as a strategy for implementing SDM in other clinical populations. Trial Registration: ISRCTN 18000391 (DOI 10.1186/ISRCTN18000391) 27/01/2016

    Big data analyses reveal patterns and drivers of the movements of southern elephant seals

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    The growing number of large databases of animal tracking provides an opportunity for analyses of movement patterns at the scales of populations and even species. We used analytical approaches, developed to cope with big data, that require no a priori assumptions about the behaviour of the target agents, to analyse a pooled tracking dataset of 272 elephant seals (Mirounga leonina) in the Southern Ocean, that was comprised of >500,000 location estimates collected over more than a decade. Our analyses showed that the displacements of these seals were described by a truncated power law distribution across several spatial and temporal scales, with a clear signature of directed movement. This pattern was evident when analysing the aggregated tracks despite a wide diversity of individual trajectories. We also identified marine provinces that described the migratory and foraging habitats of these seals. Our analysis provides evidence for the presence of intrinsic drivers of movement, such as memory, that cannot be detected using common models of movement behaviour. These results highlight the potential for big data techniques to provide new insights into movement behaviour when applied to large datasets of animal tracking.Comment: 18 pages, 5 figures, 6 supplementary figure

    Quaternary fossil fauna from the Luangwa Valley, Zambia

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    This paper describes a large collection of Quaternary fossil fauna from the Luangwa rift valley, Zambia. Stone Age artefacts have been recovered from stratified fluvial contexts, but no in situ fossil fauna have yet been recovered. We report on 500 fossil specimens collected from the surface of point bars exposed seasonally along the banks of the main Luangwa river channel. We used non-destructive x-ray fluorescence analysis of the fossils' chemical signatures to determine whether they derive from one or many primary contexts, and the relation between chemical signature and state of preservation. Specimens are identified to taxon (genus) to reconstruct palaeoenvironments and biochronology. A relatively wide range of taxa is identified, including a fossil hominin talus, described here. None of the fossils are positively attributable to extinct species, except a femur of an extinct Theropithecus reported in 2003 (Elton et al., 2003). Although no additional extinct taxa were identified, some of the remains were attributable to genera which are not currently found in this region. The results suggest that the majority of the assemblage derives from sediments which are Middle Pleistocene or later, and that past environments in the Luangwa Valley may have differed from the habitat availability found today

    A systematic review of patient reported outcome measures (PROMs) used in child and adolescent burn research

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    Crown Copyright © 2014 Published by Elsevier Ltd and ISBI. All rights reserved. Introduction: Patient reported outcome measures (PROMs) can identify important information about patient needs and therapeutic progress. The aim of this review was to identify the PROMs that are being used in child and adolescent burn care and to determine the quality of such scales. Methods: Computerised and manual bibliographic searches of Medline, Social Sciences Index, Cinahl, Psychinfo, Psycharticles, AMED, and HAPI, were used to identify Englishlanguage articles using English-language PROMs from January 2001 to March 2013. The psychometric quality of the PROMs was assessed. Results: 23 studies met the entry criteria and identified 32 different PROMs (31 generic, 1 burns-specific). Overall, the psychometric quality of the PROMs was low; only two generic scales (the Perceived Stigmatisation Questionnaire and the Social Comfort Scale) and only one burns-specific scale (the Children Burn Outcomes Questionnaire for children aged 5-18) had psychometric evidence relevant to this population. Conclusions: The majority of PROMs did not have psychometric evidence for their use with child or adolescent burn patients. To appropriately identify the needs and treatment progress of child and adolescent burn patients, new burns-specific PROMs need to be developed and validated to reflect issues that are of importance to this population

    Syndromic surveillance to assess the potential public health impact of the Icelandic volcanic ash plume across the United Kingdom, April 2010

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    The Eyjafjallajökull volcano in Iceland erupted on 14 April 2010 emitting a volcanic ash plume that spread across the United Kingdom and mainland Europe. The Health Protection Agency and Health Protection Scotland used existing syndromic surveillance systems to monitor community health during the incident: there were no particularly unusual increases in any of the monitored conditions. This incident has again demonstrated the use of syndromic surveillance systems for monitoring community health in real time

    Intratympanic methylprednisolone versus gentamicin in patients with unilateral Ménière's disease: a randomised, double-blind, comparative effectiveness trial

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    Background Ménière’s disease is characterised by severe vertigo attacks and hearing loss. Intratympanic gentamicin,the standard treatment for refractory Ménière’s disease, reduces vertigo, but damages vestibular function and can worsen hearing. We aimed to assess whether intratympanic administration of the corticosteroid methylprednisolone reduces vertigo compared with gentamicin. Methods In this double-blind comparative eff ectiveness trial, patients aged 18–70 years with refractory unilateral Ménière’s disease were enrolled at Charing Cross Hospital (London, UK) and Leicester Royal Infirmary (Leicester, UK). Patients were randomly assigned (1:1) by a block design to two intratympanic methylprednisolone(62·5 mg/mL) or gentamicin (40 mg/mL) injections given 2 weeks apart, and were followed up for 2 years. All investigators and patients were masked to treatment allocation. The primary outcome was vertigo frequency over the final 6 months (18–24 months after injection) compared with the 6 months before the first injection. Analyses were done in the intention-to-treat population, and then per protocol. This trial is registered with ClinicalTrials.gov, number NCT00802529. Findings Between June 19, 2009, and April 15, 2013, 256 patients with Ménière’s disease were screened, 60 of whom were enrolled and randomly assigned: 30 to gentamicin and 30 to methylprednisolone. In the intention-to-treat analysis (ie, all 60 patients), the mean number of vertigo attacks in the fi nal 6 months compared with the 6 months before the fi rst injection (primary outcome) decreased from 19·9 (SD 16·7) to 2·5 (5·8) in the gentamicin group (87% reduction) and from 16·4 (12·5) to 1·6 (3·4) in the methylprednisolone group (90% reduction; mean diff erence –0·9,95% CI –3·4 to 1·6). Patients whose vertigo did not improve after injection (ie, non-responders) after being assessed by an unmasked clinician were eligible for additional injections given by a masked clinician (eight patients in the gentamicin group vs 15 in the methylprednisolone group). Two non-responders switched from methylprednisolone to gentamicin. Both drugs were well tolerated with no safety concerns. Six patients reported one adverse event each: three in the gentamicin group and three in the methylprednisolone group. The most common adverse event was minor ear infections, which was experienced by one patient in the gentamicin group and two in the methylprednisolone group. Interpretation Methylprednisolone injections are a non-ablative, effective treatment for refractory Ménière’s disease. The choice between methylprednisolone and gentamicin should be made based on clinical knowledge and patient circumstances
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